CVE-2026-3902

Name	CVE-2026-3902
Description	An issue was discovered in 6.0 before 6.0.4, 5.2 before 5.2.13, and 4.2 before 4.2.30. `ASGIRequest` allows a remote attacker to spoof headers by exploiting an ambiguous mapping of two header variants (with hyphens or with underscores) to a single version with underscores. Earlier, unsupported Django series (such as 5.0.x, 4.1.x, and 3.2.x) were not evaluated and may also be affected. Django would like to thank Tarek Nakkouch for reporting this issue.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
Debian Bugs	1132927

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
python-django (PTS)	bullseye	2:2.2.28-1~deb11u2	vulnerable
	bullseye (security)	2:2.2.28-1~deb11u12	vulnerable
	bookworm	3:3.2.19-1+deb12u1	vulnerable
	bookworm (security)	3:3.2.25-0+deb12u2	vulnerable
	trixie (security), trixie	3:4.2.28-0+deb13u1	vulnerable
	forky, sid	3:4.2.30-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
python-django	source	(unstable)	3:4.2.30-1			1132927

Notes

[trixie] - python-django <no-dsa> (Minor issue)
[bookworm] - python-django <no-dsa> (Minor issue)
[bullseye] - python-django <postponed> (Minor issue)
https://www.djangoproject.com/weblog/2026/apr/07/security-releases/
Fixed by: https://github.com/django/django/commit/4412731aa64d62a6dd7edae79e0c15b72666d7ca (4.2.30)